AMBAC FINANCIAL GROUP, INC. BOARD OF DIRECTORS NAMES ROBERT J. GENADER CHIEF EXECUTIVE OFFICER

NEW YORK, January 27, 2004--Ambac Financial Group, Inc. (NYSE: ABK) (Ambac) today announced that the following people have been promoted to Senior Managing Director: Kathleen A. McDonough, William T. McKinnon, Douglas Renfield-Miller and Robert G. Shoback. Ms. McDonough is responsible for public finance - west region, general obligations, leveraged leases, domestic project finance and Ambac's expansion into Canada. Mr. McKinnon is responsible for both financial guarantee and investment portfolio credit risk management. Mr. Renfield-Miller is responsible for commercial asset-backed securities, international - non-Europe, collateralized debt obligations and financial services. Mr. Shoback is responsible for public finance - east region, structured real estate and healthcare. As previously announced in December, John W. Uhlein was promoted to Executive Vice President and is responsible for international - Europe, global utilities, global consumer asset-backed securities, structured insurance and conduits.

Robert J. Genader, Chief Executive Officer, commented, "These promotions round out the very strong senior management team of Ambac. I am very pleased that Ambac's deep base of talented professionals allows us to promote senior managers from within our own organization. People are our greatest asset and it is gratifying to reward and recognize them through promotion."

Ambac Financial Group, Inc., headquartered in New York City, is a holding company whose affiliates provide financial guarantees and financial services to clients in both the public and private sectors around the world. Ambac's principal operating subsidiary, Ambac Assurance Corporation, a leading guarantor of public finance and structured finance obligations, has earned triple-A ratings, the highest ratings available from Moody's Investors Service, Inc., Standard & Poor's Ratings Services, Fitch, Inc. and Rating and Investment Information, Inc. Ambac Financial Group, Inc. common stock is listed on the New York Stock Exchange (ticker symbol ABK).